Wireless checkout is many a grocer's dream. It's like Amazon's one-click shopping in the real world, maximizing efficiency for the customer and cutting costs for the supermarket. A new printable RFID tag could make it a reality.

RFID checkout is far from being a new idea—it's already seen small scale implementation in various pockets around the world—but it has never been cheap enough to be a viable, cashier-replacing option. Current RFID tags, made with silicon, cost about 50 cents each to produce, so stamping one on every single item in the store just doesn't make sense.

But a collaboration by researchers at Sunchon National University in Suncheon, South Korea and Rice University in Texas has yielded a new RFID tag that can be printed directly on paper or plastic packaging, eliminating the need for silicon altogether and bringing the cost down to 3 cents a tag. Now we're talking.

The invention was made possible by the wonders of nanotechnology (what isn't these days?). The researchers developed a semiconducting ink, made with carbon nanotubes, that is capable of holding an electric charge. They're currently refining their invention, trying to pack more data into smaller tags and bring the cost down to one cent each.

A fifty-fold reduction in price makes RFID a much more attractive checkout alternative. I just hope someone's still going to bag my groceries. [Wired]